Stockbyte/Thinkstock(MEXICO CITY) -- The Mexican government Wednesday released its latest tally of deaths from drug-related violence. The report says 47,515 people have been killed since President Felipe Calderon began a crackdown on drug cartel activity in 2006, according to The New York Times.

The report also shows drug-related murders increased 11 percent from January 2011 to September of that same year when compared to the same period in 2010, the Times reports.

But, the newspaper notes, experts criticize the Mexican government's apparent shortcomings in developing an adequate tracking system for trends in the country's crime, and say the newest data may be inaccurate.

"Since there are very few actual investigations, those [numbers] are approximations at best," Eric Olson, a security expert at the Woodrow Wilson International Center for scholars in Washington, told The New York Times. Olson added that there is no real way of knowing if counted murders were actually connected to organized crime or drug trafficking at all.